Progressive and regressive changes in the nucleus pulposus. Part I. The neonate.

Abstract

Magnetic resonance (MR) imaging, correlated with anatomic sections, was used to characterize the progressive and regressive changes in the nucleus pulposus in neonates. The spines of five fetuses and five full-term infants between 16 and 40 weeks old were studied. In anatomic sections, the nucleus pulposus was sharply demarcated from the anulus fibrosus, Sharpey fibers were conspicuous, and a plate of primitive notochord was evident in the equator of the disk. On long repetition time (TR)/long echo time (TE) or long TR/short TE MR images, Sharpey fibers (low signal intensity) and notochord (low signal intensity) could be differentiated from the high-signal-intensity nucleus pulposus and anulus fibrosus. The major differences between the fetal and infant spines were the amount of notochord in the disk and ossification in the vertebral body.

Temporal Association of Annular Tears and Nuclear Degeneration: Lessons from the Pediatric Population

“…These results are similar to those of previous studies highlighting the differences in the histopathology of intervertebral disks of small children compared with those of adults. Yu et al 2,15 and Ho et al 7 have described an increasing fibrous content of the nucleus from "immature" disks in the first 2 years of life to the "adult" disks after maturation, with the appearance of a well-defined firm fibrous band along the equator of the disk. Similar changes in the nucleus have been reported by Haefali et al, 9 who noted the presence of fibrous tissue peripherally in 38.4% of disks from individuals 11-30 years of age.…”

“…2,[6][7][8][9] However, representation from the first 2 decades of life has been relatively small in these studies, ranging from 19 to 50 disks, 6,9 possibly explaining a lack of direct statistical analysis focused on the young disks. Studies that do focus on the disk degeneration in children either have not included annular tears in their analysis 10,11 or have mainly looked at the clinical implications of annular tears.…”

Temporal Interactions of Degenerative Changes in Individual Components of the Lumbar Intervertebral Discs

“…The exclusion criteria were age greater than 40 years at initial MRI, presence of fractures, spondylodiskitis, tumors affecting the lumbar spine, and lumbar spinal intervention performed between the two studies. From a total of 71 subjects thus identifi ed, 8 were excluded because of the nonavailability of MRI (7) or extensive segmentation anomalies (1). A total of 378 intervertebral discs between T12 and S1 segments in the remaining 63 subjects were assessed.…”

Changes in T2 Relaxation Times Associated with Maturation of the Human Intervertebral Disk

“…4 MR imaging reveals changes in the intervertebral disk in the first 2 decades of life. [5][6][7][8][9] The intervertebral disk in the neonate is characterized by high signal intensity in T2-weighted images except in the peripheral annulus fibrosus, which has a low signal intensity sharply demarcated from the region of higher signal intensity. 5 In the adult, the disk has a less homogeneous region of high signal intensity that is less well differentiated from the surrounding outer annulus fibrosus.…”